I can not login my apple ID

Dear sir,

I'm using apple macbook air , OS version 10.8.3.

I can login my apple id to facetime, imessenger, iCloud, but I can't login to appstore, itunes store with the same id,

I've changed my password, so my password is correct, and my appstore country is China, and I select it right, and I use the same ID log to appstore just update my Macbook from 10.8.2 to 10.8.3 few days ago, it was quite ok at that time, and suddently I can't login to appstore and itunes store anymore from my Macbook, my iphone and ipad can't login either within the same wifi internet connection.

And my internet connection is fine, i can open the first page of appstore, why does this happen?

Please help me!!!

Victor zhou